African Elephant is Two Species, Researchers Say
By Richard Black
Savannah and forest elephants have been separated for at least three million years, they say, and are as distinct from each other as Asian elephants are from the extinct woolly mammoth.
Ancient and Modern
The researchers compared sequences of DNA from the nuclei of African and Asian elephants, and from woolly mammoths and the American mastodon.
All are members of the Proboscidea order of mammals.
The mastodon became extinct about 10,000 years ago - around the same time that mammoths disappeared from most of their range.
Although mastodon mitochondrial DNA has been sequenced before, the researchers say they were the first to do the analysis on DNA from the cell nucleus - in this case, using material from a tooth.
"Experimentally, we had a major challenge to extract DNA sequences from two fossils - mammoths and mastodons - and line them up with DNA from modern elephants over hundreds of sections of the genome," said Nadin Rohland of Harvard Medical School.
The genetic "distance" between the Asian elephant and the woolly mammoth turned out to be about the same as between the two African elephant species - which, the researchers say, proves the case for two distinct species in Africa now.
The picture of elephant conservation across Africa is a mixed one.
In southern countries, the animals are thriving, with populations increasing so fast that governments have had to consider culls.
However, the picture is very different in Central and West Africa, where poaching, ivory smuggling and the bushmeat trade are fragmenting populations.
If there are indeed two species, the forest dwellers are the ones most under pressure, as they tend to be found in areas where poaching and smuggling are rife.
Potentially, confirming the separation could help direct conservation efforts where they are most needed, according to Simon Stuart, chair of the International Union for the Conservation of Nature's Species Survival Commission (SSC).
"We'd have to review the evidence to see whether we need to split the African elephant into two entries on the Red List of Threatened Species," he told BBC News.
"Currently the species is listed as Vulnerable but it's possible that if there are two, one would come out in a more serious category and the other in a less serious one.
"This could be helpful for highlighting the Central African issue."
However, he cautioned, other research groups may well challenge the conclusion of the latest study, and the debate may have some way to run.